Hi all, I'm wondering how cold it has to be before camping in an RV is unwise. I live in Canada and have used my RV in some extremely cold weather. My unit is a 25' class C diesel--and I do carry a generator so that I can use the block heater to allow starting. I also have been supplementing the furnace by using a 1500 watt heater. Are there any other "polar bear" Rv'ers out there?